09: Electronic Output Devices
(click on the tabs below)
Motors
Electromagnet Motor
We were shown a DIY electromagnet motor and we brainstormed how to make the current alternate when the magnets on the spindle rotated. This would attract a magnet and just right when it is about to cross the electromagnet, it would turn negative which would repel the incoming magnet ultimately generating torque and making a motor. One way to detect the magnet getting closer to the elecrtomagnet, is by looking at the voltage that the magnet creates on the coil. Since the magnet generates a little more voltage when passing by the coil, this could trigger the current to change directions creating the motor's alternation of current.
H Bridge
This little chip basically is a connection of four switches that open and close in different variations to let a motor go backwards or forwards. This is a very helpful tool if you want a car to go backwards or forwards (I'll need it for my final project).
Stepper Motors
These motors are for exact turns of the motor. For example, you can tell it to go 1 full revolution and back 1 full revolution and it does it exactly every single time. These motors are what the ShopBot uses to drive the drillbit precisely and accurately with input code. These motors would be great for helping the mechanism of my final prototype to work. This mechanism is basically a little elevator that carries the main body of the car up/down, and moves the front wheels and back wheels together/apart (this mechanism could help the car carry longer or shorter things from point A to point B). The stepper motor could also make the car get wider with an extra set of wheels pointing sideways and one stepper motor could use a chain to turn two wheels (the ones that go down so the front facing wheels don't get stuck, and the gears that mechanically move the wheel towers apart and close to eachother).
Servo Motors
This motora basically gets an input of a certian square wave to read where you want it to move. Structurally, a servo motor is basically a potentiometer hooked up onto a motor which acts sort of like an arm that rotates a specific distance that it reads through code. These motors also have many gears inside which help it have much more torque than a DC motor.
Other Outputs
Buzzers
For buzzers, we made our own little circuits to play with the pitch and frequencies of some buzzers. We were able to make some high pitched buzzers, low pitch, and normal sounding things. We could also find Arduino code to input into the Arduino UNO to play music. For example, Kosi made his buzzer play the Harrypotter theme song with his buzzer. Overall, buzzers are a good way for making sounds that catch attention or to play music with you prototype.
LED Strips
These LED strips are baically a long strand that can be individually adressed. You can change the color, turn on and off at certain times, and brightness. You can do this with only 3 wires. These three different wires are connected to three PMW pins that act as three different channels that control different things. External libraries help in this situation because they encapsulate all the functionality of the LEDs, gives them an address, and helps them communicate with eachother. It can also help number each LED individually to controll them individually. Each LED takes up RAM so be careful when using all the LEDs cause you can use up the whole memory of the Arduino.
Output Review
In today's class, we went through a rough overview of the many output devices Robert has in his lab that we can use. We saw DC motors, servo motors, stepper motors, air/liquid pumps, etc... After doing so, we had all class to advance our understanding of these output devices for later input to our final prototypes.
Prototype Progress
I decided that it was best for me to learn how to use stepper motors and servo motors. The stepper motors would be used as the main component that "stretches" the car (final prototype in About page). The servo motors would help the "stretching" of the car by lifting one side of the car before it widens so the wheels don't grip onto the ground when movingperpendicular to their axis. Here are videos and pictures of the motors and the code corresponding to each.